Sewing machine



March 22, 1932. H. l.. DAVIS l1,850,708

SEWING MACHINE Filed March 14. 1950 2 Sheets-Sheet l March 22, 1932. H.L. DAVIS 1,850,708

SEWING MACHINE Filed March 14,' 1950 2 Sheets-Sheet 2 I-alcentedl Mer.A22, 1932 UNITED STATES PATEN'I;v OFFICE' HBBEBT. L. DAVIS, OF 'WALPOLILMASSACHUSETTS, .ASSIGNOB' T0 THE B. F. GOODBICH COMPANY, OF NEW YORK, N.Y., A CORPORATION OF NEW YORK SEWING MACHINE Application ma umn 14,1930. serial 30.435308.

This invention relates to sewing machines, and more especially to sewingmachines of the power driven type.

The chief objects of the invention are to effect improved quality of thework; `to increase production; to render the sewing operation less-laborious; and to provide a sewing machine by which the foregoingobjects are accomplished,

Of the accompanying drawings: Fig. 1 is an end elevation of my improvedsewing machine in its preferred form, parts being'broken away and insection.

Fig. 2 is a front elevation of the sewing machine shown in Fig. 1.

. Fig. 3 is a section, on a larger scale, on

line 3-3 of Fig. 1.l

Fig. 4 is a detail sectional viewon a larger scale, of a portion of theclutch mechanism shown in Fig. 3. Fig. 5 is a detail sectional view ofvalve 41V and associated parts.

Fig. 6 is a diagrammatic view showing the operative range .of anindexing. mechanism with relation to the angular positions of the driveshaft of the sewing machine.

Briefly stated, my invention comprises a power driven sewing machine incombination with indexing mechanism which automatically advancesoperative parts of the machine to determine positions when the drivingpower is disconnected. The indexingr mechanism is associated with themechanisms for operating the needle or needles of the machine and thepresser-foot, and serves to lift the same out ofengagement with the workwhenever the machine is stopped.

Referring to the drawings, 10 is a bench or table upon which is mounteda power driven sewing machine 11 of the usual type used for heavyindustrial work. The Vsewing machine is provided with the usual needle12 (Fig. 2), presser-foot 13, and feed-pawl (not shown) co-operatingwith the 'latter for advancing the work. l The aforesaid mechanisms areactuated-by the usual drive-shaft 14, which is provided on its outer endwith a pulley 15,

and the latter is connected by a transmisf sion belt 16 with a pulley 17journaled on a stub-shaft 18, which stub-shaft is mounted in a bracket19 secured to theunder side of the table 10. f

One lateral face of the pulley 17 is provided with a friction disc 20adapted frictionally to engage the adjacent lateral face of "aconstantly driven pulley 21 also journaled on the stub-shaft 18 andconnected by a transmission belt 22 with a suitable source of motivepower (not shown). The opposite lateral face of the pulley 17 is formedwith a laterally eX- oo tending hub portion 23 which has a rounded andclosed end portion. An `Lshaped member 24 mounted adjacent the end ofthe pulley-hub 23 is formed with a brake-shoe 25 adapted to engage theperipheral face of the hub, which thereby serves as a brake-drum, tostop the rotation of the pulley 17 quickly when it is desired to stopoperation of the machine. The member 24 also is formed with a face-cam26 adapted to engage the rounded end portion of the hub 23 for urgingthe pulley 17 into rictional driving engagement with the pulley 21 toactuate the operative parts of the sewing machine.

The member 24 is mounted for vertical movement, in the upper limit ofwhich the brake shoe 25 is in engagement with" the. pulley-hub 23, thecam 26 is exerting no axial pressure against the end of the hub, and theoperative parts of the machine are stationary. In the lowermost positionof the member 24, which is the full-line position of the parts shown inFig. 2, the brake-shoe 25 is retracted from the hub 23 and the cam 26 isurging the pulley 17 into frictional driving engagement withtheconstantly driven pulley 21.

A tension spring 27 connected with the member 24 and to the under sideof the table 10 normally urges the said member upwardly. An adjustablelink 28 connects the member 24 with a foot-treadle 29 swivelled inbrackets 30, 30 on the iioor beneath the table 10, whereby the operatoris enabled to depress the said member, against the tension of the spring27 to start the operation of the machine in the usual manner.

A rearwardly Nwextending bracket 31 is mounted upon the Esewing machine11 at the same end thereof as the pulley 15 and somewhat below thelatter. The bracket 31 sup- 10 .a source of pressure ports a fiuidpressure cylinder 32 which is obliquely disposed at such an angle thatits extended axis is substantially tangent to the pulley 15. Thecylinder 32 is provided with the usual piston 33, and with a piston rod34 which extends from its forward end. The rear end of the cylinder isopen, and pressure fluid is admitted to and vented from the cylinder atits forward end, between the piston and the end wall, through an inletand out` pipes 35, 38 in communication with each other whereby thecylinder 32 is charged. In its lowermost position the bottom of theplunger 39 rests upon and closes the inlet port 41 of the supply pipe38, putting the pipes 35, 37 in communication with each other throughthe open valve seat 40, as shown, whereby .the cylinder 32 is vented ordischarged.

A lever 42 pivoted at 43 in the casing of thevalve 36 engages the upperend of the plunger 39, and a tension spring 44 of sufiicient strength todepress the plunger 39 against the pressure of the Huid isconnected tothe lever 42 adjacent its free end and to the valve casing. The free endof the lever 42 is connected by a two-part lost-motion link to thefoot-treadle 29, one portion 45 of said link being connected to thelever 42 and an' other portion 46 thereof being connected to thetreadle. Secured to the lower end of the member 45 at spaced apartpositions are respective collars 47' and 48, and a compression spring 49is mounted upon the member between the lower collar 48 and a block 50slidably mounted upon the member 45' and secured to the member 46.

The arrangement is such that when the foot-treadle 29 is in raisedposition the block A 50 is in engagement with the collar 47 and liftsthe link-member 45 and lever 42 against the tension ofthe spring 44 andpermits the fluid pressure in the pipe 38 to lift the valveplunger 39and thereby to open the inlet port 41 and to charge the cylinder 32through the pipe 35 with pressure fiuid from said pipe 38. When thetreadle is depressed the spring 44 effects the immediate depression ofthe lever 42 to lower the valve-plunger 39, and

thereby to discharge the cylinder 32 through the pipes 35', 37, beforethe pulley 17 is fully in driving relation with the pulley 21 towardwhich it is moved by the cam 26. After the lever 42 is in loweredposition, further movement of the link-member 46 draws the block .Y

50 away from the collar 47 against the force of the springI 49. Thus inthe reverse or upward movement of the treadle the rotation of the pulley17 is stopped before the cylinder is c arged.

'In a sewing machine of the character herein provided, one revolution ofthe driveshaft 14 effects one operative cycle, that is, a downward andan upward movement of the needle, the needle being in engagement withthe work during substantially half or 180 of the shafts revolution andout of engagement therewith for the same period. My improved indexingmeans comprises clutch mechanism operating in an arc of 270 and adaptedo eratively to engage and rotate the drive-sha t, upon occasion, uponthe stopping of the machine with the needle not at the maximum raisedposition denoted by the medial 90 degrees of the aforesaid 180 of theshafts rotation during which the needle i is raised from the work. Thuswith the stoppin(r of the sewing machine the indexin m-edhanisminstantly rotates the drive-sha forwardly and stops it at a positionwhere the needle is raised sufficiently to permit manipulation of thework, if said drive-shaft, by chance, already is not in such position.The range of the indexing mechanisms operation with relation to theangular positions of the drive-shaft is graphically illustrated in Fig.6.

The indexing mechanism comprises a disc or pulley 51 journaled on asuitable bearing 52 mounted upon a bushing 53 on the driveshaft 14, saiddisc being positioned between the pulley 15 and the machine housing, andformed on its periphery with three flanges which define two grooves. Theface of the pulley 15 adjacent the disc 51 is formed with a concentricgroove 54, and projectin thereinto is a fixed stud 55 which has itseading edge beveled or tapered as shown in Fi s. 3 and 4. Slidablymounted in the wall o the disc 51 parallel to the axis thereof is a pinor detent 56 the forward end or nose of which extends into the orbit ofthe stud 55, the detent being yieldingly1 maintained in this position bya leaf-spring 57 engaging its rear end-portion. The nose of the detent56 is beveled complemental to the stud 55 as shown, the arrangementbeing such that when the disc 51 is stationary the stud 55 depresses andpasses over the detent during each revolution of the pulley 15. The disc51 is rotatable in either direction, and, when the pulley 15 isstationary and the disc rotated in a counterclockwise direction, thedetent 56 is adapted to engage the stud 55 and to rotate the pulley 15and shaft 14 a limited distance depending upon the position at which thedetent engages the stud.

For so rotating the disc`51, counter-clocktion, and for movin the pistonrod 34 outwardly during the 'scharging of thecylinder 32, a cable orchain. 59 1s' mounted in the other peripheral groove of the disc 51 andone of its ends is secured to the disc and its other end is secured to'one end of a tension s ring 60, the other end of the tension springeing secured to an extension 61 of the bracket 31.

For raising the presser-foot 13 from the work substantially concurrentlywith the raising of the needle therefrom, the forked end of a lever 62engages the under side of a collar 63 mounted upon the stem 64 of thepresser-foot, said lever 62 being pivotally mounted at 65 on the machineframe and having its opposite end connected by a link 66 to aA stud 67extending laterally from one end of la lever 68. The other end of saidlever is secured to one end of a rock-shaft 69 which is journaled in thebracket 31 and has 'its otherv end provided with a fork-end rocker-arm70 straddling the piston-rod 34 adjacent the` closed end of cylinder 32.The outer end ofthe piston-rod 34 is provlded 'with va flange or collar71 adapted to engage the rocker-arm 70 at substantially the limit of thepiston-rods inward movement during the charging of the cylinder 32, andby rocking said rocker-arm and the rock-shaft 69,k to actuate the partsconnected therewith comprising the lever 68, link 66 and lever 62 toraise the forked end of the latter and with it the presser-foot 13. Acompression spring 72 is mounted upon the lstem 64 of the presserfootbetween the collar 63 thereon and a guide 73 in which said stem slidesfor normally urging the presser-foot downwardly toward operativeposition.

In the operat-ion` of the -apparatus'the operator uses both hands tomanipulate the work at all times and operates the machine solely withher feet. When not in operation, the cylinder 32 is charged, the pistonrod 34 is in lretracted position within the cylinder,

Y and the needle 12 and'presser-foot 13 are in raised positionpermitting the work to be easily and quickly placed in position forsewing. To start vthe machine the operator depresses the toe portion ofthe treadle 29 to thel full line position of the drawings, with theimmediate result that the link 45-46 is lowered and the valve 36operated to close `the {luid-inlet port 41 therein and to dischar e thecylinder 32 through the pipes 35 and 3 This permits the spring 60 tocontract,.there` b y rotating the disc 5l in a clockwise direc` tion asviewed in Fig. 1, and drawing the piston-rod 34 to its projectedposition shown in said figure. As the collar 71 on the piston rodreleases the rocker-arm 70, the spring 72 on the presser-foot stem movessaid presserfoot downwardly to operative position upon the work. Theforegoing operations are ef fected before continued downward movement ofthe treadle releases the brake 25 from the hub 23 and the cam 26 forcesthe pulley 17 into frictional'driving engagement with the constantlydriven pulley 21, to drive the machine.

To stop the machine, the toe of the treadle 29 is raised, permitting thespring 27 to draw the member 24 upwardly, thus moving the cam 26 fromthe hub 23 and applying the brake 25 thereto to stop the machine. Theblock 50-v then engages the collar 47 on the link 45 and lifts the lever42 against the tension'of the -spring 44, thereby permitting thepressure fluid in the pipe -38 to raise the plunger 39 and to seat thesame in the valveseat`40 to close 0H the exhaust pipe 37 and to permitsaidpressure fluid to enter the pipe 35 to charge the cylinder 32. Asthe piston rod 34 of the cylinder moves rearwardly against the tensionof the spring 60, the disc 51 is rotated counter-clockwise as viewed inFig. 1. I the pulley 15 has stopped with the stud 55 thereof elsewherethan in the 90 langle corresponding to the uppermost osition within thescope of the appended claims.-

I claim:

1. The combination, with a sewing machine of the power-driven type, ofclutch mechanism associated with sald power drive, fluid pressureoperated means for concurrently raising the needle and the presser-footof the machine, a valve associated with said fluid pressure operatedmeans, and meanscommon to said valve and said clutch mechanism foroperating the same in timed relation.

2.1The combination, with a sewing machine including a shaft, of apulleyixed to said shaft, drive-means for said pulley, a disc journaledon said shaft beside said pulley, clutch means on said disc adapted toengage said pulley, and means for imparting determinate reciprocatoryangular movement to said disc of less than `360 degrees.

3. The combination, with a sewing machine including a shaft, of powermeans for normally driving said shaft, auxiliary shaftdriving meansincluding a, single acting uid pressure cylinder for turning said shaftangularly when the power means is disengaged, and means forautomatically resetting said last-named means.

4. The combination, with a sewing machine including a shaft, o'f powermeans for normally driving said shaft, auxiliary shaftdriving meansincluding a fluid pressure cylinder for turning said shaft angularlywhenthe power means. is disengaged, and presserfoot-lifting mechanismassociated with said fluid pressure cylinder.

In witness whereof I have hereunto. set my hand this 12th day ofFebruary, 1930.

HERBERT L. DAVIS. i I

